Paper maker&#39;s drier felt



June30, 1931.

' T. HINDLE PAPER MAKERS DRIER FELT Filed Jan. 28. 1930 v INVENTOR H gfimwwwa such a Patented June 30, 1931 TES PATENT OFFICE 'rnoMAs nmnrm, or HASHINGDEN, ENGLAND The invention relates to drier PAPER MAKERS DRIER FELT Application filed January as, 1930. Serial No. 424,077.

felts by which the wet web of paper is carried through and pressed against the drying cylinders in paper making machines.

A. drier felt on a paper machine making paper acts to press the cessively against the cylinders. the combined effects 0 wet web of paper suc-' steam heated revolving The drier felt is thus subject to f heat and chemicals absorbed from the paper and to mechanical wear and tear by reverse ing cylinders and ending around the drythe smaller intermediate rollers. Cotton is comparatively quickly hydrolized by the combined efiects of heat and chemical action and degree that it 'the mechanical strain so loses its strength to is unable to withstand s at which stage the cotton drier felt must be renewed.

It has been proposed to make drier felts wholly of wool slnce this fibre will withstand heat and certain chemical action to afar greater degree than is the case with cotton.

However, such woolen drier felts are necessarily of considerable-thickness also they are heavy and not possess readily retains an .ture,'so retarding ing of the paper.

the

sequence .of their thickness,

relatively very expenslve.

the desirable de'greeof porosity, and the large amount of wool involved too excessive amount of mois- They do efiicient and rapid dry- Such woolen felts in mm are generally either durmg weaving or prior Their excessive thicks a sewn-j oint or seam being used as is desirable for ease of fitting in the case of drier felts intended for wide, fast'run ning paper machines. able thickness is requ A drier felt of reasonired if the sewn-joint is to be used, otherwise the joint is too thick. and

clumsy, and is liable has also been propos with a wool weft but The object of this to mark the paper. It ed to make a drier felt with a cotton warp.

invention is to provide an improved drier felt which will have the resistance of wool to heat and chemical and .;mechanical actions without the disadvantageous large molsture holding effect of the known woolen drier felt and very pronounced porosity, while ample strength may be provided with a reason able thickness thus enacross the -tional cotton warp yarns.

The drier felt shown in Fig. 1 is of known four-shaft weave woven with face warp threads a wholly of worsted yarn, back warp threads 6 wholly of cotton yarn and weft threads 0 wholly of cotton yarn. The warp threads at are of single or multi-ply worsted yarn, the warp threads threads B are of multiply cotton yarn and the weft threads 0 are of multi-ply cotton yarn. The resulting drier felt has one face wholly of worsted warp yarn and a back wholly of cotton warp the former of which contacts with paper when in use on the paper machine.

A out one-third of the drierfelt shown in Fig. 1 consists of worsted warp, the remaining two-thirds being cotton. The

worsted-used is employed to the very best as it is in intimate contact with negligible proportlons, and which is relafelt consists of worsted, the 7 drier felt is relatively very small. Furthermore, the cotton backing warp and weft act to take up the moisture from the worsted face, being in close contact therewith, the cotton back dissipating themoisture very readily into the atmosphere.

The drier felt shown in Fig. 2 is of known six-shaft weave woven with face warp threads a wholly of worsted yarn back warp threads 6 wholly of cotton yarns forming the middle and back layers and Weft threads a wholly of cotton yarns about two-ninths of the drier felt shown in Fig. 2 consists of worsted. the remaining seven-ninths being cotton. The moisture holding capacity is therefore even less than with the form shown in Fig. 1.

In either example Fig. 1 or Fig. 2 the worsted warp threads at are much coarser or thicker than the cotton warp threads 6 and the cotton weft threads 0 thereby producing a dense or crowded worsted face for the working surface of warp yarn and an open or porous cotton back due to the clearance provided between the adjacent threads. The worsted warp threads a are so proportioned that the diameter ofthe threads multiplied by the number of threads per inch is greater than unity and the cotton warp threads I) are so proportioned that the diameter of the threads multiplied by the number of threads per inch is equal to or less than unity.

The weft or transverse threads 0 are wholly of cotton, but the worsted warp yarns a, when proportioned as above, completely cover the cotton weft, which is therefore protected since the Weft cannot contact with the paper or cylinders. The above proportions also ensure such a density or crowding of the worsted warp yarns a that shrinkage in Width is negligible-not more than 1% per centwhen the drier felt is running on the paper machine. To secure these advantages, and to limit stretch longitudinally, it is essential that the drier felt should be woven on a loom of suitable strength and rigidity, as the warp yarns must be maintained under very great tension during weaving.

The crowding of the worsted warp threads, resulting from the above described proportions, gives the drier felt pronounced transverse rigidity, which effectively prevents the drier felt running into a crease, so that roping is completely avoided.

As will be apparent to those skilled in the trade, both forms of drier felt herein described can be woven from warp drawn from a bobbin creel directly to the loom.

The improved drier felt, after weaving, is ready for immediate use on the paper machine, no milling or other finishing process being required.

What I claim as my invention and desire to protect by Letters Patent is 1. An improved drier felt comprlsmg a working face wholly of Worsted warp yarns coarser and thicker than the back cotton warp yarns, a back of cotton warp yarns finer and thinner than the worsted face yarns and a weft wholly of cotton yarn finer than the worsted warp yarns constituting a dense or crowded Worsted face of Warp yarn for the working surface and an open or porous cotton back. i

2. An improved drier felt having the working surface consisting wholly of worsted warp yarns, and the back warps and weft consisting wholly of cotton yarns, thinner and finer than the Worsted warp yarns in which the worsted yarns are so proportioned that the yarn diameter multiplied by the number of warp threads per inch is greater than unity, and the cotton yarns are so proportioned that the yarn diameter multiplied by the number of warp threads per inch is equal to or less than unity.

In testimony whereof I have hereunto set my hand.

THOMAS HINDLE. 

